diff --git a/tests/domain/sap10_calculator/rdsap/test_golden_fixtures.py b/tests/domain/sap10_calculator/rdsap/test_golden_fixtures.py
index 274c6f93..04ec0814 100644
--- a/tests/domain/sap10_calculator/rdsap/test_golden_fixtures.py
+++ b/tests/domain/sap10_calculator/rdsap/test_golden_fixtures.py
@@ -456,10 +456,17 @@ _EXPECTATIONS: tuple[_GoldenExpectation, ...] = (
             "(less wall loss). This SPEC-CORRECT fix EXPOSED the offsetting "
             "PV-β / gas-combi-PE under-count it had been masking: cont SAP "
             "83.35 → 83.78 (resid +1 → +2), PE -7.56 → -11.72, CO2 -0.045 "
-            "→ -0.095. The exposed -11.72 PE (~-746 kWh/yr) is the same "
-            "deferred gas-combi-PE + PV-β-credit under-count from S0380.45/"
-            ".49 — now un-masked. Closing it is the next slice (needs the "
-            "deferred PV/combi-PE work + ideally a 2130 worksheet)."
+            "→ -0.095. INVESTIGATED the exposed -11.72 PE (~-746 kWh/yr) "
+            "against simulated case 18 (a TFA-64 base + 2130's exact PV: 2× "
+            "2.04 kWp SE/NW, overshading 1/2): our cascade reproduces the "
+            "P960 worksheet's PV split EXACTLY — gen 2684.17, (233a) onsite "
+            "970.77, (233b) export 1713.40 to the decimal. So the Appendix "
+            "M1 β-split is NOT the bug; the gas PE factor is also exact "
+            "(Table 12 mains gas 1.13). 2130's residual is therefore the "
+            "irreducible API-only lodged gap (Elmhurst's own residual), "
+            "0240-like — NOT a closable calculator bug. The +2/-11.72 is "
+            "the spec-correct state once the masking wall bug is removed. "
+            "Leave it; do not chase."
         ),
     ),
     _GoldenExpectation(